Sensitivity to depth relief on slanted surfaces.
Glennerster, A. and McKee, S. P. (2004)
Journal of Vision, 4, 378-387
http://journalofvision.org/4/5/3/, doi:10.1167/4.5.3
Reprints can be downloaded from Journal of Vision or here pdf .
Abstract
The finest stereoacuity is known to depend on the disparity of a
target relative to other visible points. Here we show that a more
important factor in determining sensitivity to displacement can be the
disparity of a target relative to an invisible interpolation plane
through other neighbouring points. We tested the sensitivity of
observers to displacements of the central column of a regular grid of
dots that was either fronto-parallel or slanted about a vertical axis.
We found that subjects' sensitivity to displacement was better
predicted by a model based on the disparity of a target with respect
to the grid plane than it was by a model based on disparity with
respect to other reference points. In control conditions carried out
on one subject we found that this result did not depend on adaptation
to the grid slant since it also occurred when the direction of grid
slant varied from trial to trial. Nor did it depend on the perception
of slant, because the data were similar for trials on which the grid
was perceived as approximately fronto-parallel or markedly
slanted. Our results indicate that sensitivity to the depth component
of the target displacement is based on disparity relative to a local
reference plane.
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